Rota, Gian-Carlo; Kahaner, D; Odlyzko, A (1973). “On the foundations of combinatorial theory. VIII. Finite operator calculus”. Journal of Mathematical Analysis and Applications42 (3): 684–760. doi:10.1016/0022-247X(73)90172-8. ISSN0022247X.
Rota, Gian-Carlo; Kahaner, D; Odlyzko, A (1973). “On the foundations of combinatorial theory. VIII. Finite operator calculus”. Journal of Mathematical Analysis and Applications42 (3): 684–760. doi:10.1016/0022-247X(73)90172-8. ISSN0022247X.